Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said:

أَحْبِبْ حَبِيبَكَ هَوْنًا مَا عَسَى أَنْ يَكُونَ بَغِيضَكَ يَوْمًا مَا وَأَبْغِضْ بَغِيضَكَ هَوْنًا مَا عَسَى أَنْ يَكُونَ حَبِيبَكَ يَوْمًا مَا

Love your beloved moderately, for perhaps he will become hateful to you someday. Hate the one you hate moderately, for perhaps he will become your beloved someday.

Source: Sunan At-Tirmidhi 1997, Grade: Sahih

Zaid ibn Aslam reported: Umar ibn Al-Khattab, may Allah be pleased with him, said:

لا يَكُنْ حُبُّكَ كَلَفًا وَلا بُغْضُكَ تَلَفًا

Let not your love be infatuation and let not your hatred be destruction.

It was said, “How is this?” Umar said:

إِذَا أَحْبَبْتَ كَلِفْتَ كَلَفَ الصَّبِيِّ وَإِذَا أَبْغَضْتَ أَحْبَبْتَ لِصَاحِبِكَ التَّلَفَ

When you love someone, you become infatuated like a child. When you hate someone, you love destruction for your companion.